Primeval black holes, entities that (according to what scientists believe) may have existed around the time when the universe began. Although we have never actually detected one of these black holes, we do know that they were not formed in the usual fashion, there was no dying star that collapsed in on itself and gave birth to these black holes. This is because when the universe was formed, there were not stars old enough to die and collapse, in fact, the universe was completely devoid of old stars for around the first one billion years.
Scientists believe that these black holes were created by the vast clouds of matter that were present at that time, these clouds were the building blocks of pretty much everything that exists in the universe. Some of these clouds gathered so much mass that they began to collapse into their own gravity wells and as a result, they formed these super massive black holes that are some of the oldest entities in the universe.
Keep in mind that this is all based on theory, no one has managed to actually detect one of these black holes so far so nothing is set in stone. However, the day we get to discover these marvels may not be that far now, The Georgia Institute of Technology released a paper that claims that NASA’s JWST (James Webb Space Telescope) will have the technological capabilities needed to pick up signs of these black holes. The JWST is set to be launched in a number of years (hopefully within a decade), and the best part is that the telescope is going to be so sensitive that it will take relatively lesser time to identify one of these black holes.
There has already been a lot of research on these Direct Collapse Black Holes (DCBH) that has helped us determine what effects these black holes have on their surroundings. We know that DCBHs result in the formation of metal-free stars with short live spans in their surrounding galaxies. Based on this information, the JWST could focus on galaxies that have smaller amounts of metal in them, further reducing the time it would take the telescope to find a DCBH.
We also know that emerging direct collapse black holes produce electromagnetic radiation at a high frequency that can be picked up by the JWST. However, these radiations will undergo redshifting (their wavelengths will become longer) as they travel across huge distances, this could lead to complications if the telescope were to solely rely on radiation detection. The biggest problem with trying to study older parts of the universe is that light that they produce is faint, old, and travels over incomprehensively large distances, making it quite difficult to detect these light waves and make sense of them.
Scientists continue to hope that the JWST will be able to provide them with answers to their previously unanswered questions, but they are also sure that these answers will give rise to countless more questions.